algo/fix: some issues TA points out

7e1810-algo_hw/hw1.typ

@@ -74,6 +74,6 @@ What is the largest $k$ such that if you can multiply $3 times 3$ matrices using
 
   Assuming $n = 3^m$. Use block matrix multiplication, the recursive running time is $T(n) = k T(n\/3) + O(1)$.
 
-  Using master theorem, the largest $k$ to satisfy $log_3 k < lg 7$ is $k=21$.
+  When $log_3 k > 2 $, using master theorem, the largest $k$ to satisfy $log_3 k < lg 7$ is $k=21$.
 
 ]

7e1810-algo_hw/hw9.typ

@@ -27,7 +27,7 @@ $
 Explain why the modified algorithm is correct, and explain in what sense this change constitutes an improvement.
 
 #ans[
-  If $P[q+1]!=T[i] "and" P[pi[q]+q]=P[q+1]!=T[i]$, there's no need to compare $P[pi[q]+q]$ with $T[i]$, because $P[pi[q]+q]$ is the same as $P[q+1]$, so we can directly compare $P[q+1]$ with $T[i]$. This change improves the efficiency of the algorithm.
+  If $P[q+1]!=T[i] "and" P[pi[q]+1]=P[q+1]!=T[i]$, there's no need to compare $P[pi[q]+1]$ with $T[i]$, because $P[pi[q]+1]$ is the same as $P[q+1]$, so we can directly compare $P[q+1]$ with $T[i]$. This change improves the efficiency of the algorithm.
 ]
 
 #align(center)[